1. Field of the Invention
The present invention relates to a land grid array socket for electrically connecting an electronic package such as an integrated circuit (IC) chip with a circuit substrate such as a printed circuit board (PCB), and particularly to a socket adapted for receiving a land grid array (LGA) package therein and electrically connecting the LGA package with a PCB.
2. Description of the Prior Art
An IC package having contact pads arranged on a floor thereof in a land grid array is known as an LGA package.
Connectors for removably mounting an LGA package on a PCB are known as LGA sockets. An LGA socket typically comprises an insulative housing, a plurality of electrical contacts received in the housing, a metal clip pivotably mounted to an end of the housing, and a lever pivotably mounted to an opposite end of the housing for engaging with the clip.
Referring to FIGS. 5 to 7, a conventional LGA socket is illustrated. The LGA socket comprises an insulative housing 2′ receiving a plurality of contacts (not shown) therein, a stiffener 4′ attached to the housing 2′, a clip 5′ pivotably mounted to an end of the stiffener 4′, and a lever 6′ pivotably mounted to an opposite end of the stiffener 4′ for engaging with the clip 5′. The housing 2′ comprises a floor 20′, two opposite first sidewalls 26′ and two opposite second sidewalls 24′ adjacent to the first sidewalls 26′. A plurality of passageways 22′ is defined in the floor 20′, for receiving corresponding numbers of contacts therein. The contacts each protrude outwardly from a top portion of the housing 2′, for connecting with the contact pads (not shown) of the LGA package 3′. Bosses 265′, 266′ are respectively formed on the first sidewalls 26′, for positioning and keying the LGA package 3′ in the housing 2′. Notches 32′, 34′ are defined in the LGA package 3′, for interferingly engaging with the bosses 265′, 266′ of the housing 2′. The LGA package 3′ is, thereby, retained in the housing 2′. A step 263′ is formed at each side of the floor 20′ and in communication with the first sidewalls 26′, for supporting two opposite side of the LGA package 3′ thereon.
In use, the LGA package 3′ is disposed on the housing 2′. The clip 5′ is rotated down onto the LGA package 3′, with pressing portion (not labeled) of the clip 5′ resting on the LGA package 3′. Then, the lever 6′ is rotated down, for fastening the clip 5′. In this position, the clip 5′ is pressed by the lever 6′, and the pressing portion of the clip 5′ presses on the LGA package 3′ tightly.
The clip 5′ defines a pair of securing portion 51′ at one end of the clip 5′, and the corresponding side of the stiffener defines a pair of slots 41′ for engaging with the securing portion 51′. During the rotation of the clip 5′, the clip 5′ first presses one side of the LGA package 3 that is near to the securing portion 51′ of the clip 5′, and the opposite side that is far from the securing portion 51′ is not pressed. Therefore, the unpressed side of the LGA package will move upwardly and even depart from the predetermined horizontal place. When the clip 5′ is substantially oriented at a horizontal position parallel to the top surface of the housing, the raised side will be finally pressed down onto the step 263′. Because the horizontal displacement of the LGA package 3′, the LGA package 3′ is prone to scrape corresponding sidewall 26′ of the housing 2′ during being pressed to predetermined position. The scrape will affect the electrical characters of the LGA socket and even damage the housing 2′.
Furthermore, when the LGA package is slantways positioned in the housing, with one side of the LGA package 3′ resting on the step 263′ and the opposite side abutting against corresponding first sidewall 26′. When the lever 6′ is rotated down to press on the clip 5′, the pressing portion of the clip 5′ pushing down on the LGA package 3′. Then the LGA package 3′ moves downwardly under the pressing force of the clip 5′ applied by the lever 6′, sides of the LGA package 3′ near the first sidewalls 26 abutting against and urging inner surface of the corresponding first sidewalls 26. Accordingly, scraping of inner surface of the first sidewalls 26′ happens. As a result, the housing 2′ is prone to be damaged, and reliability of the electrical connection between the LGA package 3′ and the contacts of the housing 2′ is accordingly decreased.
In view of the above, a new land grid array socket which overcomes the above-mentioned disadvantages is desired.